The present invention relates to a power supply circuit and a method for controlling the power supply circuit. The present invention relates to, for example, a power supply circuit provided with a plurality of voltage sources, and a method for controlling the power supply circuit.
Energy harvesting technology for converting surrounding energy such as optical energy, vibrational energy, thermal energy, and radio waves (electromagnetic waves) into power has received attention in recent years. Use of the energy harvesting technology eliminates the need to install batteries in electronics, thereby improving the convenience of the electronics.
Japanese Patent No. 2959657 discloses electronic-related technology that is capable of enhancing the degree of freedom of usage of a plurality of batteries to improve the use efficiency of the batteries. Japanese Unexamined Patent Application Publication No. 2006-20491 discloses a technique concerning an electronic having a power supply wherein a voltage of power to be supplied is low, a booster circuit that boosts the power to a voltage with which a load circuit can be operated, and the load circuit operated by the power boosted by the booster circuit.
When the energy harvesting technology is used, the voltages obtained in respective voltage sources are extremely low. It is therefore necessary to provide a voltage control circuit in order to increase the voltage of each voltage source to the level where the electronics can be driven.